Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations provided, the description carries the full burden of behavioral disclosure. It transparently states the $0.001 USDC payment requirement, the returned fields, and the composite score range. It does not mention response format or failure behavior, but the paid nature and output scope are valuable and clearly disclosed.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is two tight sentences with no redundancy. The first sentence front-loads the tool's purpose and outputs, and the second covers the parameter format and payment requirement, making every sentence useful.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a single-parameter tool with no annotations and no output schema, the description provides the essential invocation details: pair format, output fields, and cost. It could be more complete by describing the response structure or error cases, but the core information an agent needs to call it successfully is present.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The schema provides only the parameter name 'pair' with zero description coverage. The description compensates fully by defining the expected format as a Coinbase pair id and giving the concrete example BTC-USDC, which is exactly what an agent needs to construct a valid invocation.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description opens with 'Single-pair crypto lookup', giving a specific verb and focused resource scope. It clearly enumerates the outputs: USDC price, composite signal score (-100..+100), ATR%, and reasons, making the tool's purpose concrete and distinguishable from broader tools like signals or report.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The use case is implied through 'Single-pair crypto lookup' and the Coinbase pair id example, which tells an agent this tool is for one specific pair. However, it does not explicitly contrast itself with sibling tools or state when not to use it, leaving the routing decision partly to inference.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.